Last week, a man muttering to himself under his breath walked into a convenience store in St. Louis took a donut and a few cans of soda and marched back outside. The man, later identified as 23-year-old Kajiemi Powell continued to talk to himself angrily and pace back and forth. The police were called as a man recorded the incident on his cell phone.

There is 12 seconds between when the cops pull up and when they begin handcuffing Powell’s lifeless body. In the interim, he was shot nearly a dozen times.

Now, before you attribute this as yet another example of runaway police violence, there are some important differences between what happened to Powell and what happened to Michael Brown, the unarmed teenager shot only a few miles away in the adjacent town of Ferguson. In this case, the man was wielding a large knife, and possible had a second one in his pocket. He also continually screamed at cops, challenging them to kill him. “You are going to have to kill me before you take me to jail,” he was heard saying. During the incident, he appears to have started rushing at the cops (although that detail is somewhat in dispute). In short, Powell was clearly unstable, armed and behaving aggressively.

The cops killed him.

The officers and the department they work for have claimed that this was a clean operation. The man was dangerous, the cops shot him like they are trained to do. But, when you take the number of incidents like what happened to Powell and add them together you begin to see a picture of hairpin triggers and the incredibly frequent number of so-called “justifiable homicides.” When we look at the police records in similar Western countries, we don’t seem this same level of violence. Police, like citizens in some states, have a “Stand Your Ground” policy and they exercise it freely.

To understand how unusual this is, we need to look at examples from other parts of the world. Let’s look at a specific case in the United Kingdom, where cops were presented with an equally troubled man with an even larger knife (a machete, in fact) and compare the police response.

In the video, a man wielding a massive blade wanders in front of Buckingham Palace. The police, including some mounted on horses, kept onlookers at a safe distances. Other officers surround the man on all sides. At a moment where the man is distracted, one officer flanks him and fires a taser, dropping the man almost instantly. A dozen cops rush the convulsing man and promptly arrest him. Presumably he is either in jail or, more likely, getting help at a psychiatric facility. One thing for certain: the man’s not dead and not a single bullet was needed.

It’s efforts like this one that make it unsurprising that English police officers rarely kill people. In 2012, Channel 4 looked into how often officers fired their weapons and found that in the last two years British cops had discharged their weapons just 5 times. Just twice were they used to fatally injure a suspect. The idea that cops could kill someone is so offensive to the English mindset that after one such incident, thousands of Londoners rioted in the streets in protest.

By contrast, nobody knows how many people American police kill because not standardized way of measuring this seemingly very important bit of information exists, but the closest number researchers have come up with is roughly 400 a year. Sure, America is larger; but not that much larger. Sure, America is more violent, but not that much more violent. There is something else going on here.

Police in America seem all to willing to shoot-to-kill instead of finding non-lethal solutions. Are most cops homicidal psychopaths? Of course not, but the policing culture has certainly shifted towards viewing their role as occupiers in dangerous territory rather than protectors of citizens. The bigger, badder military toys they insist they need attest to that. Somewhere along the way – if I had to guess, it would be right after 9/11 – the police started viewing the world as much more dangerous. They needed bigger guns, stronger cars, and more lethal tactics to combat the perception (if not the reality) that the streets they were policing had turned against them.